8 - Forest-desert alternation history revealed by the pollen-record in lake baikal over the past 5 million years

Abstract

The watershed of Lake Baikal constitutes the southern portion of the Siberian taiga and the northern part of the Mongolian steppe, and it is located at a high-latitude (51–56 N), far from the ocean. The paleoclimatic history of the Baikal region sensitively reflects past global changes, such as warm-cold and dry-moist oscillations of climate. Paleovegetational reconstruction of the region is indispensable to understanding how the Siberian taiga forest responded in timing and magnitude to past global changes. However, there are few palynological studies for paleovegetational reconstruction of the past million years in the region. This chapter presents a palynological study on the BDP96 Hole 1 core drilled by a Russian scientific drilling team in 1996. The results obtained in this study prove that the forest-desert alternations are closely related to global glacial–interglacial cycles during the Pleistocene. Considerable forest retreats are visible for relatively long periods during the late Pliocene, and a remarkable desert prevailing period during the early and middle Pliocene preceded the forest dominant period. The work in the Baikal area has also shown that these forest-desert alternations are more sensitive to global paleoclimate changes than those found in other continental region records.